Confocal

In geometry, '''confocal''' means having the same foci: confocal conic sections.

* For an optical cavity consisting of two mirrors, confocal means that they share their foci. If they are identical mirrors, their radius of curvature, ''R''_mirror, equals ''L'', where ''L'' is the distance between the mirrors. * In conic sections, it is said of two ellipses, two hyperbolas, or an ellipse and a hyperbola which share both foci with each other. If an ellipse and a hyperbola are confocal, they are perpendicular to each other. * In optics, it means that one focus or image point of one lens is the same as one focus of the next lens.

==See also== *Confocal laser scanning microscopy *Confocal microscopy *{{section link|List of orbits|Eccentricity classifications}} {{set index article|mathematics}}

Category:Elementary geometry Category:Optics